C# Testing Framework Loop Through Test Cases

Question

I am looking to use MS testing framework to test a tax calculator and needs to run over 100 test cases. As see below, I have set up an array of testCases and loop through each but the when I run Tests, it only returns one return.

Question:

1. Is there a way for every test display result?
2. How do I return each test results? Currently, the system only returns values if failed.

            [DataTestMethod]
            public void CalculateResult(int val)
            {

                // arrange
                int[] testCase = { 1000,2000, 35000, 400003, 59509 };

                foreach (int income in testCase)
                {

                    double expectOutput = TaxCalculator(income);

                    // act
                    
                    SUT.GeneralTaxRule generalTaxationRule = new SUT.GeneralTaxRule(income);
                    
                    double actualOutput = generalTaxationRule.getTax();

                    // assert
                    Assert.AreEqual(expectOutput, actualOutput);
                    Console.WriteLine(expectOutput, actualOutput);
                }

            }

Answer 1

When you use DataTestMethod attribute you should have attributes for each DataRow

[DataTestMethod]
[DataRow(1000)]
[DataRow(2000)]
// etc
public void CalculateResult(int income)
{
    double expectOutput = TaxCalculator(income);

    // act                        
    SUT.GeneralTaxRule generalTaxationRule = new SUT.GeneralTaxRule(income);                        
    double actualOutput = generalTaxationRule.getTax();

    // assert
    Assert.AreEqual(expectOutput, actualOutput);
    Console.WriteLine(expectOutput, actualOutput);
}

Another way you might achieve the same is using DynamicData attribute

[DataTestMethod]
[DynamicData(nameof(TestData), DynamicDataSourceType.Method)]
public void CalculateResult(int income)
{
    double expectOutput = TaxCalculator(income);

    // act                        
    SUT.GeneralTaxRule generalTaxationRule = new SUT.GeneralTaxRule(income);                        
    double actualOutput = generalTaxationRule.getTax();

    // assert
    Assert.AreEqual(expectOutput, actualOutput);
    Console.WriteLine(expectOutput, actualOutput);
}

public static IEnumerable<object[]> TestData()
{
    yield return new object[] { 1000 };
    yield return new object[] { 2000 };
    /// etc.
}

You could data drive the data however you like in TestData above (eg a file, a database, or hardcoded). There is other options for DynamicDataSourceType as well which you could investigate.

Answer 2

Using Xunit, you could do it like this:

private static int[] incomesArray = { 1000,2000, 35000, 400003, 59509 };

public static IEnumerable<object[]> GetIncomeTestData =>
                incomesArray
                .Select(x => new object[] { x })
                .ToArray();

[Theory]
[MemberData(nameof(GetIncomeTestData))]
public void CalculateResult(int income)
{
    // arrange
    var expectOutput = TaxCalculator(income);
    var generalTaxationRule = new SUT.GeneralTaxRule(income);
                
    // act            
    var actualOutput = generalTaxationRule.getTax();

    // assert
    Assert.Equal(expectOutput, actualOutput);
}

You can have as many values in incomesArray as you'd like and you'll be able to see the result for each test value.

Answer 3

If you're using a [DataTestMethod] you can add test cases through one or more [DataRow(...)] attribute(s):

[DataTestMethod]
[DataRow(1000)]
[DataRow(2000)]
[DataRow(35000)]
[DataRow(400003)]
[DataRow(59509)]
public void CalculateResult(int val)
{
    double expectOutput = TaxCalculator(val);

    // act  
    SUT.GeneralTaxRule generalTaxationRule = new SUT.GeneralTaxRule(val);
    double actualOutput = generalTaxationRule.getTax();

    // assert
    Assert.AreEqual(expectOutput, actualOutput);
    Console.WriteLine(expectOutput, actualOutput);
}

That way you can inspect the test result for each val in the Test Explorer window.